13-101055303-C-T

Variant names:

• chr13-101055303-C-T
• rs757937802
• NM_052867.4:c.5209G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP2

The NM_052867.4(NALCN):​c.5209G>A​(p.Asp1737Asn) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D1737H) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NALCN NM_052867.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.86
• Publications: 0 publications found

Genes affected

NALCN (HGNC:19082): (sodium leak channel, non-selective) This gene encodes a voltage-independent, nonselective cation channel which belongs to a family of voltage-gated sodium and calcium channels that regulates the resting membrane potential and excitability of neurons. This family is expressed throughout the nervous system and conducts a persistent sodium leak current that contributes to tonic neuronal excitability. The encoded protein forms a channelosome complex that includes G-protein-coupled receptors, UNC-79, UNC-80, NCA localization factor-1, and src family tyrosine kinases. Naturally occurring mutations in this gene are associated with infantile neuroaxonal dystrophy, infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF) syndrome, and congenital contractures of the limbs and face with hypotonia and developmental delay (CLIFAHDD) syndrome. A knockout of the orthologous gene in mice results in paralysis with a severely disrupted respiratory rhythm, and lethality within 24 hours after birth. [provided by RefSeq, Apr 2017]

NALCN-AS1 (HGNC:42743): (NALCN antisense RNA 1)

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the NALCN gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 63 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Gene score misZ: 4.9555 (above the threshold of 3.09). Trascript score misZ: 6.7536 (above the threshold of 3.09). GenCC associations: The gene is linked to congenital contractures of the limbs and face, hypotonia, and developmental delay, temporal lobe epilepsy, hypotonia, infantile, with psychomotor retardation and characteristic facies 1, Sheldon-hall syndrome, digitotalar dysmorphism, hypotonia, infantile, with psychomotor retardation and characteristic facies, Freeman-Sheldon syndrome.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NALCN	NM_052867.4	c.5209G>A	p.Asp1737Asn	missense_variant	Exon 44 of 44	ENST00000251127.11	NP_443099.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NALCN	ENST00000251127.11	c.5209G>A	p.Asp1737Asn	missense_variant	Exon 44 of 44	1	NM_052867.4	ENSP00000251127.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.060	T
BayesDel_noAF	Benign	-0.15
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.18	T
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.88	D
M_CAP	Uncertain	0.16	D
MetaRNN	Uncertain	0.50	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	0.55	N
PhyloP100		5.9
PrimateAI	Uncertain	0.71	T
PROVEAN	Benign	-1.0	N
REVEL	Uncertain	0.48
Sift	Uncertain	0.010	D
Sift4G	Pathogenic	0.0	D
Polyphen		0.99	D
Vest4		0.45
MutPred		0.30		Gain of relative solvent accessibility (P = 0.1571);
MVP		0.76
MPC		0.43
ClinPred		0.86	D
GERP RS		5.4
Varity_R		0.26
gMVP		0.60
Mutation Taster		=47/53	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs757937802; hg19: chr13-101707655;